I. Fine hepatic control of glucose metabolism will continue to be evaluated in newborn animals (lambs and puppies) in response to steady state glucose infusions. The failure to promptly cease hepatic output during hyperglycemia will be related to (a) hormonal levels of insulin and glucagon and (b) to persistence of gluconeogenesis. The latter will be determined indirectly by assessing conversion of labeled lactate or alanine to glucose during measurement of glucose turnover with glucose-6-T by the Steele steady state infusion technique. Verification of persistence of hepatic output by hepatic vein catheterization will also be performed. II. Dr. Susa will continue studies of the specific protein factor (ferrous or metal ion++ dependent) which activates phosphoenolypyruvate carboxykinase. Since this factor may be important in controlling one of the key mechanisms for gluconeogenesis, it will be further identified in fetal and neonatal guinea pigs of different gestational age. The relationship of the protein factor and PEPCK will be evaluated in vitro systems. III. Hemoglobin AIc (glycohemoglobin) will be assesed in pregnant (normal and diabetic) women for effects on oxygen dissociation (ODC). Factors which influence ODC such as pH, pCO2, 2,3-DPG, ATP and ADP will be examined and related to fetal growth (size) and outcome. The relationship between maternal glucose control, HbAIc and neonatal erythropoiesis will also be examined. BIBLIOGRAPHIC REFERENCES: Schwartz, R.: Total Parenteral Nutrition in Infancy, in Current Pediatric Therapy. Eds. Gellis, S.S. and Kagan, B.M., W.B. Saunders Co. pg. 7-10, 1976. Schwartz, A.L., Schwartz, R. and Schwartz, H.C.: Effect of Hypoxia on Erythroblasts from Avian Fetal Liver: Adenosine Triphosphate Levels and Hemoglobin Synthesis. Pediat. Res., 10:796, 1976.